It has become the ultimate symbol of American resolve against the threat of North Korea: a visit by the U.S. commander in chief to “freedom’s frontier,” the heavily guarded demilitarized zone that has separated the North and South for 64 years.

Wearing bomber-style jackets, surrounded by military officers, peering through binoculars, all but one president since Ronald Reagan has gazed across the barren strip of land at the 38th parallel from an observation post – and been moved to talk tough. In April, Vice President Mike Pence, undertaking the same solemn ritual, said he toured the DMZ so the North Koreans could “see our resolve in my face.”

But as President Donald Trump prepares for a 12-day swing next month through five Asian nations to bolster international pressure on Pyongyang, the administration is divided over whether he should make the pilgrimage, an issue that remains unresolved. Some aides worry a visit could further inflame already heightened tensions on the Korean Peninsula, while others have expressed concern over Trump’s personal safety, according to people who have spoken to administration officials.

Asian foreign policy veterans of both the Obama and George W. Bush administrations said it would be foolish for Trump not to go. But the White House is facing opposition from South Korean President Moon Jae-in’s administration and the U.S. State Department over fears that a visit would ratchet up Trump’s war of words with North Korean dictator Kim Jong Un.

A White House spokesman declined to comment, saying the administration was not ready to release the full itinerary for Trump’s trip, which is scheduled to last from Nov. 3 to Nov. 14.

People watch as a screen shows footage of the launch of a Hwasong-12 rocket, beside a billboard advertising North Korea's Pyeonghwa Motors (R), in Pyongyang on September 16, 2017.
North Korea said on September 16 it was seeking military "equilibrium" with the United States as leader Kim Jong-Un vowed to complete Pyongyang's nuclear programme. /KIM WON-JIN/AFP/Getty Images

Kcna Via Kns /, AFP/Getty Images

This undated picture released from North Korea's official Korean Central News Agency (KCNA) on Sept. 16, 2017 shows North Korean leader Kim Jong-Un inspecting a launching drill of the medium-and-long range strategic ballistic rocket Hwasong-12 at an undisclosed location.
Kim vowed to complete North Korea's nuclear force despite sanctions, saying the final goal of his country's weapons development is "equilibrium of real force" with the United States, state media reported on September 16.

Ahn Young-joon, The Associated Press

A woman watches a TV screen showing a file footage of North Korea's missile launch, at the Seoul Railway Station in Seoul, South Korea, Friday, Sept. 15, 2017.

In this photo provided by South Korea Defense Ministry, a Taurus missile fired from a South Korean air force F-15K fighter jet hits a target during a drill, off the country's western coast, South Korea, Wednesday, Sept. 13, 2017. South Korea says it conducted its first live-fire drill for an advanced air-launched cruise missile it says will strengthen its pre-emptive strike capability against North Korea in the event of crisis. (South Korea Defense Ministry via AP).

Eugene Hoshiko, The Associated Press

A man watches a TV news program on a public screen showing an image of North Korean leader Kim Jong Un while reporting North Korea's possible nuclear test in Tokyo Sunday, Sept. 3, 2017. South Korea's military said Sunday that North Korea is believed to have conducted its sixth nuclear test after it detected a strong earthquake, hours after Pyongyang claimed that its leader has inspected a hydrogen bomb meant for a new intercontinental ballistic missile.

Shizuo Kambayashi, Associated Press file

In this Aug. 6, 2017, file photo, a man takes a photo of a TV news program in Tokyo, showing an image of North Korean leader Kim Jong Un. U.N. experts say North Korea illegally exported coal, iron and other commodities worth at least $270 million to China and other countries including India, Malaysia and Sri Lanka during the six-month period ending in Aug. in violation of U.N. sanctions.

KRT via AP Video, Associated Press file

In this Dec. 12, 2012 file image made from video, North Korea's Unha-3 rocket lifts off from the Sohae launching station in Tongchang-ri, North Korea. North Korea's top governing body warned Thursday, Jan. 24, 2013 that the regime will conduct its third nuclear test in defiance of U.N. punishment, and made clear that its long-range rockets are designed to carry not only satellites but also warheads aimed at striking the United States.

Greg Baker, AFP/Getty Images

The North Korean town of Sinuiju (at rear) is seen behind the Friendship Bridge (L) which connects Sinuiju and the the Chinese border city of Dandong, and the Broken Bridge (R), in Dandong, in China's northeast Liaoning province on Sept. 4, 2017.
Countries around the world swiftly condemned North Korea's announcement that it had tested a hydrogen bomb on September 3, with South Korea calling for the "strongest punishment" against Pyongyang while key ally China strongly condemned it. The Broken Bridge was bombed during the Korean War and now reaches only half way across the river.

Greg Baker, AFP/Getty Images

Lights are seen in the North Korean town of Sinuiju, behind the Friendship Bridge (L) which connects Sinuiju and the the Chinese border city of Dandong, and the Broken Bridge (R), in Dandong, in China's northeast Liaoning province on Sept. 3, 2017.
Countries around the world swiftly condemned North Korea's announcement that it had tested a hydrogen bomb on September 3, with South Korea calling for the "strongest punishment" against Pyongyang while key ally China strongly condemned it. The Broken Bridge was bombed during the Korean War and now reaches only half way across the river.

Yonhap, AFP/Getty Images

South Korea's Capital Defense Command soldiers take part in a military drill in Seoul on Sept. 4, 2017.
Following North Korea's sixth nuclear test, South Korean President Moon Jae-In called for the "strongest punishment" while top military officers in Seoul and Washington vowed a joint "military counteraction" at the earliest date.

Ahn Young-joon, The Associated Press

South Korean army's K-1 tanks move during a military exercise in Paju, South Korea, near the border with North Korea, Monday, Sept. 4, 2017. Following U.S. warnings to North Korea of a "massive military response," South Korea's military on Monday fired missiles into the sea to simulate an attack on the North's main nuclear test site a day after Pyongyang detonated its largest ever nuclear test explosion.

Greg Baker, AFP/Getty Images

A North Korean soldier stands on the bank of the Yalu river near the North Korean town of Sinuiju, opposite the Chinese border city of Dandong, in China's northeast Liaoning province on Sept. 4, 2017.
The five-nation BRICS grouping meeting in China said on September 4 it "strongly deplores" North Korea's latest nuclear test, adding to global condemnation of Pyongyang.

Ahn Young-joon, The Associated Press

South Korean army soldiers take positions with their K-55 self-propelled howitzers during a military exercise in Paju, South Korea, near the border with North Korea, Monday, Sept. 4, 2017. North Korea said it set off a hydrogen bomb Sunday in its sixth nuclear test, which judging by the earthquake it set off appeared to be its most powerful explosion yet.

Korean Central News Agency/Korea News Service via AP

In this undated image distributed on Sunday, Sept. 3, 2017, by the North Korean government, shows North Korean leader Kim Jong Un at an undisclosed location. North Korea’s state media on Sunday, Sept 3, 2017, said leader Kim Jong Un inspected the loading of a hydrogen bomb into a new intercontinental ballistic missile, a claim to technological mastery that some outside experts will doubt but that will raise already high worries on the Korean Peninsula. Independent journalists were not given access to cover the event depicted in this image distributed by the North Korean government. The content of this image is as provided and cannot be independently verified.

Eugene Hoshiko, Associated Press file

In this Aug. 29, 2017 file photo, Japanese Air Self-Defense Force (JASDF) demonstrates the training to utilize the PAC-3 surface to air interceptors at the U.S. Yokota Air Base in Fussa, on the outskirts of Tokyo. Japan is debating whether to develop limited pre-emptive strike capability and buy cruise missiles - ideas that were anathema in the pacifist country before the North Korea missile threat. Japan currently has a two-step missile defense system, interceptors on destroyers in the Sea of Japan, and if they fail, surface-to-air PAC-3s.

Yonhap News/Newscom/Zuma Press/TNS

North Korean leader Kim Jong-un presides over a military parade held in Pyongyang to mark the 105th birthday of late founder Kim Il-sung on April 15, 2017.

Wong Maye-E, Associated Press file

In this April 15, 2017, file photo, North Korean leader Kim Jong Un waves during a military parade in Pyongyang, North Korea. North Korea said Tuesday, Aug. 15, 2017 that leader Kim Jong Un was briefed on his military's plans to launch missiles into waters near Guam as part of an effort to create "enveloping fire" near the U.S. military hub in the Pacific.

KRT via AP Video

This image made from video aired by North Korea's KRT on Aug. 26, 2017 shows a photo of North Korean leader Kim Jong Un inspecting soldiers during what Korean Central News Agency called a "target=striking contest" at unknown location in North Korea.

Kim Kwang Hyon, The Associated Press

North Koreans watch a televised news broadcast of the test-fire of a ballistic rocket Wednesday in Pyongyang, North Korea. On Tuesday, North Korea fired an intermediate-range missile directly over Japan -- the type of missile that could reach American, South Korean and Japanese military bases in northeast Asia.

Lee Jin-man, Associated Press file

In this Tuesday, April 23, 2013, file photo, a North Korean soldier looks at the southern side through a pair of binoculars at the border village of Panmunjom, which has separated the two Koreas since the Korean War, in Paju, north of Seoul, South Korea. Threatening to fire a volley of missiles toward a major U.S. military hub _ and the home to 160,000 American civilians _ may seem like a pretty bad move for a country that is seriously outgunned and has an awful lot to lose. But pushing the envelope, or just threatening to do so, is what North Korea does best.

Ahn Young-joon, The Associated Press

South Korean army soldiers patrol along the barbed-wire fence in South Korea's Paju near the border with North Korea, Friday, Aug. 11, 2017.

Yosuke Mizuno. Kyodo News via AP

A PAC-3 interceptor unit arrives at a garrison of the Japan Ground Self-Defense Force in Kaita, Hiroshima prefecture, southwestern Japan, Saturday, Aug. 12, 2017. Japan started deploying land-based Patriot interceptors after North Korea threatened to send ballistic missiles flying over western Japan and landing near Guam. The Defense Ministry said Friday the PAC-3 surface-to-air interceptors are being deployed at four locations - Hiroshima, Kochi, Shimane and Ehime.

Asked during a news conference this week whether a DMZ visit would provoke Pyongyang, Trump said the trip’s details were not finalized and added: “I didn’t hear in terms of provoking, but we will certainly take a look at that.”

Trump has already done plenty of provoking amid reports that North Korea’s ballistic missile and nuclear weapons programs are making more rapid advances than expected. Trump has repeatedly mocked Kim as “Little Rocket Man,” and he declared during a United Nations speech last month that the United States is prepared to “totally destroy” the North if necessary.

Kim has responded with his own harsh rhetoric, he called Trump a “mentally deranged U.S. dotard,” and by threatening to strike Guam and test a nuclear device over the Pacific Ocean.

Trump will have plenty of other chances to talk tough, starting with a tour of the Pearl Harbor military base in Hawaii on his way to Asia. In Tokyo, the president is scheduled to meet with the parents of a Japanese girl kidnapped by North Korean agents four decades ago, and in Seoul, he will deliver a speech to the South Korean national assembly.

But current and former U.S. officials said a presidential visit to the DMZ sends a more pointed message to the American and South Korean troops who patrol the border region just 30 miles north of Seoul – as well as the enemies forces on the other side – that the United States remains committed to the bilateral defense treaty that has been in place since the armistice that halted fighting in the Korean War in 1953.

“The DMZ functions as a kind of amplifier,” said Daniel Russel, who served as assistant secretary of state of East Asian and Pacific affairs under President Barack Obama and is now a senior fellow at the Asia Society. “The message takes on a more martial and ominous tone when it comes out of a military command post on North Korea’s doorstep.”

George H.W. Bush is the only president since Reagan toured the DMZ in 1983 not to visit, although Bush did make his own trip while serving as Reagan’s vice president.

Obama visited the DMZ during a 2012 trip to Seoul for a nuclear summit, telling the troops that “the contrast between South Korea and North Korea could not be clearer, could not be starker, both in terms of freedom but also in terms of prosperity.”

In 1993, President Bill Clinton told reporters during a DMZ tour that if the North ever used nuclear weapons “it would be the end of their country.” Clinton walked so far across the Bridge of No Return that joins the two Koreas that U.S. Secret Service agents reportedly brought rifles into the area to protect him, in violation of the Korean War cease-fire.

Officials in Seoul and Tokyo are eager for Trump to reaffirm his commitment to the U.S. defense treaties with its East Asian allies. The president has unsettled Moon and Japanese Prime Minister Shinzo Abe by criticizing U.S. trade imbalances with those nations, pulling out of a 12-nation Asia Pacific trade accord and demanding a renegotiation of a bilateral trade pact with South Korea that Obama signed in 2011.

At the same time, Moon’s advisers fear that a Trump visit to the DMZ could increase the chances of a miscalculation that could provoke a military confrontation or have other unintended consequences, such as harming Asian financial markets or disrupting planning for the Winter Olympics, which will be held in PyeongChang in February.

Evan Medeiros, who served as senior Asia director at the National Security Council under Obama, said Trump “needs to be crystal clear” over the United States position on North Korea and suggested that the costs of not visiting the DMZ could be greater than going.

“If he doesn’t go, guess what the next story is?” said Medeiros, who accompanied Vice President Joe Biden to the DMZ in 2013.

Already some foreign policy experts are mocking the White House’s hesitation. On Tuesday, Jeffrey Lewis, a nuclear nonproliferation expert who operates a popular Twitter account, included a chicken emoji with his retweet of a South Korean news report that U.S. and South Korean officials were steering Trump away from the DMZ.

Former U.S. officials emphasized that Trump’s national security team could craft a visit that achieves the symbolic message – speaking to the troops, touring Observation Post Ouellette – without directly provoking the North with hostile words.

But they acknowledged that the president, who would be accompanied by reporters, is prone to straying off message.

“We’ve never had a president go to the DMZ who has implied the U.S. is preparing for preventative war with North Korea,” said Michael Green, who served as senior Asia director at the NSC under president George W. Bush.

In Feb. 2002, Bush visited the DMZ less than a month after he had called North Korea, Iran and Iraq the “axis of evil” during his State of the Union address. The president’s speechwriters proposed having Bush deliver remarks akin to Reagan’s seminal “tear down this wall” speech in West Berlin in 1987.

But Green said Bush’s team eventually came to conclude that such a moment could be misinterpreted as a provocative call for regime change in Pyongyang. Instead, they sent him to the Dorasan Train Station near the border to call on the North to open an uncompleted railway between the two countries.

“Like the United States, South Korea has become a beacon of freedom, showing to the world the power of human liberty to bring down walls and uplift lives,” said Bush, who also visited the DMZ observation post. “Today, across the mines and barbed wire, that light shines brighter than ever. It shines not as a threat to the North but as an invitation.”

As much of the country was gripped Wednesday by horrific images from the mass shooting at a Florida high school, two dozen senior Trump administration officials worked frantically into the night to thwart what they considered a different national security threat.

Mitt Romney’s extensive resume has many Republicans looking to him to take on a role in the Senate as a political and moral counterweight to a president many in the GOP see as divisive and undignified.